Tips: Take care of your folds at the beginning, and the rest should be fairly easy if you follow the tutorial exactly. Making careful folds, and making sure everything is properly aligned will allow you to get best results for the final product. This rule is something that should probably be kept in mind when making any origami model. Other than that, have fun!

About Creepers:

The Creeper is a hostile mob that will ambush players and explode, causing damage to the player and the surrounding blocks and entities. Unlike Zombies and Skeletons, Creepers will not catch fire in direct sunlight, meaning they can wander around unharmed any time of the day until it is killed or despawns. However, the creepers will still be aggressive during the day. Creepers spawn in the overworld at night and in locations with a light level of 7 or less, just like regular hostile mobs. They are especially dangerous as they are almost completely silent (except for footsteps and their hissing noises when ready to explode).Their explosion is devastating at short range. Creepers run from Cats and Ocelots[1] and will even ignore the player to run away when a feline is too close. The Creeper has gained considerable notoriety among Minecraft players for their infuriating habit of sneaking up on the player and hurting them and damaging structures. Creepers are one of two mobs that can never be targeted by any other mob. The other being the Ghast (with the latter's exception of Zombie Pigmen). Allied and utility mobs that can attack other hostile mobs, such as Tamed wolves, Snow Golems and Iron Golems will never purposely attack Creepers. This is because of their destructive nature upon being provoked.

For more info check out this link: http://www.minecraftwiki.net/wiki/Creeper